The Arizona Cardinals are pessimistic that running back Adrian Peterson will be able to play in Sunday's matchup against the Los Angeles Rams, though he is considered a game-day decision, a source told ESPN's Adam Schefter. Peterson is listed as questionable with a neck injury. On Friday night, Peterson told ESPN's Josh Weinfuss that he's "feeling pretty good" after not practicing all week because of the injury, which happened Sunday against Jacksonville. Cardinals coach Bruce Arians said Friday afternoon that Peterson is the type of player who doesn't need to practice to play.